The present invention relates to compositions useful as surgical hand preparations and antimicrobial hand lotions. More specifically the invention relates to stable hydroalcoholic compositions thickened using nonionic or cationic polymers.
Control of nosocomial infection and exposure to infectious disease is of paramount concern to doctors, nurses, and clinicians who work in hospitals and surgery centers. One of the most effective methods for controlling infection is regimented hand disinfection before and possibly after each patient contact and particularly before and after each surgical procedure. Hand disinfection is generally accomplished using antimicrobial soaps with water. These soaps are usually formulated to include either povidone-iodine (usually 7.5% by weight) or chlorhexidine digluconate (CHG) (usually 2% or 4% by weight) as the active antimicrobial agent. In addition, these formulated soaps may contain surfactants and possibly low levels of humectants such as glycerin.
Hand disinfection is also accomplished using presurgical scrub replacements. These are used instead of the soap and water scrub. Presurgical scrub replacements ideally achieve bacterial kill equal to or better than a traditional soap and water scrub and in a shorter period of time. Additionally, they maintain or improve the skin""s natural barrier to microbial and chemical contamination while providing acceptable tactile properties. Examples of presurgical scrub replacements include hydroalcoholic gels which generally include high levels of either ethanol or isopropanol as the disinfecting agent and also include a thickener and optionally a humectant (e.g., glycerin).
To date, thickeners used in hydroalcoholic gels have been based primarily on anionic polymers such as polyacrylic acid (sold under the tradename xe2x80x9cCARBOPOLxe2x80x9d by BF Goodrich Specialty Polymers and Chemicals Division of Cleveland, Ohio). See, for example, U.S. Pat. No. 4,956,170 (Lee) and U.S. Pat. No. 5,167,950 (Lins). These compositions are generally incompatible with cationic compounds such as chlorhexidine gluconate. There are a few reports of nonionic and cationic polymeric thickeners being used as well. See, for example, U.S. Pat. No. 4,478,853 (Chausee) and International Publication No. WO 93/007903 (Deckner). These hydroalcoholic compositions have relatively low levels of alcohol, generally too low to provide rapid and effective antimicrobial activity.
U. S. Pat. No. 5,512,199 (Khan) discloses a hydroalcoholic wipe composition, incorporating nonionic and cationic polymeric emollients or humectants. These compositions have very low viscosities, too low to be used as a lotion. U.S. Pat. No. 4, 981,678 (Tomlinson) and U.S. Pat. No. 4,981,698 (Tomlinson) provide hydroalcoholic biocidal compositions incorporating low molecular weight polymeric emollients such as polyglycerol and polyvinyl pyrrolidone. These polymers do not provide adequate thickening in hydroalcoholic lotions.
In other hydroalcoholic systems, such as those described in U.S. patent application Ser. Nos. 08/493,714 and 08/493,695 (both of which were filed on Jun. 22, 1995 and assigned to 3M Company), nonionic, anionic, cationic, or zwitterionic emulsifiers are used as thickeners for a wide range of concentrations of alcohol, without the need for a polymeric thickener such as polyacrylic acid. Although these systems are highly desirable, other high viscosity hydroalcoholic compositions useful as an antimicrobial lotion, for example, are still needed.
This invention provides compositions useful as products for skin disinfection such as presurgical hand preparations and lotions that are easily washed off hands with water, preferably with no apparent residue. The preferred compositions of this invention, in general, have a very nice feel after both single and multiple applications. Preferred compositions maintain or improve the skin condition after multiple applications with no slimy or abnormal feeling noticed during post application hand washing. When used as a presurgical scrub replacement, this invention achieves bacterial, fungal, and viral kill equal to or better than a traditional soap and water scrub in a shorter period of time while maintaining or improving the skin""s natural barrier to microbial and chemical contaminants. Additionally, these compositions are compatible with cationic additives, such as chlordexidine digluconate. The invention overcomes the shortcomings of past compositions by providing a viscous cosmetically elegant lotion that is substantially nontacky and maintains or improves skin condition and is compatible with cationic additives. Further, the composition has a cosmetically elegant feel and may be dispensed as a lotion or as a foam.
One embodiment of the present invention is an antimicrobial hydroalcoholic composition comprising: a hydroalcoholic solvent system comprising a lower alcohol and water in a weight ratio of at least about 50:50; a thickener system comprising at least one cationic polymeric thickener that is solid at ambient temperature; wherein the cationic thickener is selected such that the composition has a viscosity of at least about 10,000 centipoise at 23xc2x0 C.; wherein the thickener system is present in an amount of at least about 0.5% by weight, based on the total weight of the composition; and a secondary antimicrobial agent.
Another embodiment is an antimicrobial hydroalcoholic lotion comprising: a hydroalcoholic solvent system comprising a lower alcohol and water in a weight ratio of at least about 60:40; a thickener system consisting essentially of one or more nonionic polymeric thickeners, at least one of which is solid at ambient temperature; wherein the one or more polymeric thickeners are selected such that the composition has a viscosity of at least about 4,000 centipoise at 23xc2x0 C.; and further wherein the thickener system is present in an amount of at least about 0.5% by weight, based on the total weight of the composition; and a secondary antimicrobial agent.
Yet another embodiment of the invention is an antimicrobial hydroalcoholic lotion comprising: a hydroalcoholic solvent system comprising a lower alcohol and water in a weight ratio of at least about 60:40; a thickener system comprising at least one associative polymeric thickener that is solid at ambient temperature; wherein the associative polymeric thickener is selected such that the composition has a viscosity of at least about 4,000 centipoise at 23xc2x0 C.; wherein the thickener system is present in an amount of at least about 0.5% by weight, based on the total weight of the composition; and a secondary antimicrobial agent.
xe2x80x9cAmbient temperaturexe2x80x9d as used herein refers to the temperature range of about 21-25xc2x0 C.
xe2x80x9cEmollientxe2x80x9d as used herein refers broadly to materials which are capable of maintaining or improving the moisture level, compliance, or appearance of the skin when used repeatedly.
xe2x80x9cEmulsifierxe2x80x9d as used herein is synonymous with xe2x80x9csurfactantxe2x80x9d and refers to molecules comprising hydrophilic (polar) and hydrophobic (non-polar) regions on the same molecule.
xe2x80x9cEmulsionxe2x80x9d as used herein refers to a stable dispersion of one liquid in a second immiscible liquid. Emulsion also refers to stable dispersions of a solid in an immiscible liquid wherein the solid was formed by cooling below the freezing point of the solid composition.
xe2x80x9cLotionxe2x80x9d means liquid or cream, free of any propellant.
xe2x80x9cPolymerxe2x80x9d as used herein refers to a natural, modified-natural, or synthetic molecule having repetitive units and a number average molecular weight of at least about 20,000.
xe2x80x9cSolvent,xe2x80x9d xe2x80x9csolvent system,xe2x80x9d or xe2x80x9chydroalcoholic solventxe2x80x9d as used herein refer to the alcohol and water combination in the present invention.
xe2x80x9cStablexe2x80x9d as used herein refers to a composition that displays less than or equal to 10% by volume separation after centrifuging at 1545xc3x97g for 30 minutes at ambient temperature.
xe2x80x9cSurfactantxe2x80x9d as used herein is synonymous with xe2x80x9cemulsifier,xe2x80x9d the definition of which is given above.
xe2x80x9cThickener Systemxe2x80x9d as used herein refers to at least one nonionic or cationic polymer that is solid at ambient temperature.